Process for producing monovinyl acetylene



Patented May 16, 1939 UNITED STATES PROCESS FOR PRODUCING MONO ACETYIEHerbert Berg and 'Hans Heim, Burghansen, and Franz Leiss, Munich,Germany, assignors to Dr. Alexander WackerGesellschaftiiirElektrochemische Industrie, G. in. b. H., Munich, Bavaria, Germany, acorporation No Drawing. Original application July '7, 1937,

Serial No. 152,374.

Divided and this application April 23, 1938, Serial Nor 203,816. InGermany July 17, 1936 12 Claims.

This invention relates to the production of monovinyl acetylene and is adivision of our application Serial No. 152,374, filed July 7, 1937'.

The principal object of the invention is to provide a new and improvedprocess for producing monovinyl acetylene. I

Another object of the invention is to provide an improved process forproducing monovinyl acetylene in the vapor phase by passing acetylene atelevated temperatures over solid copper-containing ternary catalysts.

We have made the surprising discovery that when using non-acid catalystsaccording to our process the expected explosive copper-acetylenecomposition is not produced, but that a practically completetransformation of the acetylene into monovinyl acetylene is effectedwithout appreciable by-products, when the catalyst is com- Cal posed ofthree definite components of the type hereinafter described.

The catalyst, according to our invention, comprises a cuprous salt whichis in itself useless, and which must be activated by suitable additions.Such activators, the effect of whichapparently rests on their complexformation with the cuprous salts, comprise organic compounds containinga plurality of hydroxyl groups, specifically aliphatic polyhydricalcohols and sugar, including such allphatic polyhydric compounds asglycols, e. g., butylene glycol, glycerine, mannitol, sorbitol, dulcite,and the like; and, with these substances, salts of metals 'of the first,second and third groups of the periodicsystem are present with inclusionof rare earths, predominantly the water soluble ones, particularly thehalogenides, e. g.,

chlorides. r The production of the catalyst is appropriately effected insuch a way that the initial products in dissolved or suspended conditionare placed upon a suitable carrier and the latter is then dried. Forinstance. chloride and glycerine are heated with some water and thesuspension is placed upon appropriate carriers, e. g., pots'herds,pumice stone and the like, upon which'it is dried. After drying in aninert gas or in vacuum, the catalyst is ready for use. Of course it isalso possible to produce the catalyst in such a manner that the desiredcompounds are formed on the carrier by chemical combination.

The acetylene reaction is preferably effected at temperatures over 100C. The temperature range, in which the catalyst is active, changesaccording to the nature of the catalyst employed; in mostcases a rangeof 100-180 c.

cuprous chloride, magnesium has been found suitable. The process is notlimited to any definite pressure, but the course of the reaction may beinfluenced by changing the pressure. For example, by increasing thepressure the conversion is improved and the monovinyl acetylene may becondensed and/or separated oil from the waste gases by cooling with tapor main water.

It is advantageous to mix with the acetylene which enters the reactionchamber small quantities of a volatile acid, such as acetic acid,propionic acid or butyric acid, or it may be thinned or diluted withinert gasessuch as nitrogen. Since the catalyst becomes very stronglyheated during the reaction, it is generally advantageous to cool it, forexample by external cooling of the reaction chamber, or by an excess ofacetylene or by addition of an inert gas. Furthermore, through an excessof acetylene or admixture .of an inert gas, the monovinyl acetylenewhich is generated is very quickly removed from the reaction chamber andthus the formation of byproducts is stillfurther retarted. The gas whichleaves the reaction chamber may be used again in carrying out thereaction. Before being returnedv to the reaction chamber, the reactionproducts are appropriately removed, wholly or in part, as by cooling,absorption, adsorption, or dissolution, and fresh acetylene isadvantageously added in accordance with the quantity used up.

, The monovinyl acetylene obtained according to the process hereindescribed is suitably used for chemical conversions, as in theproduction of artificial masses and'thelike.

Example 1 150 cc. of water on a boiling water bath, and

after addition of pumice stone while being stirred it deposits on thesame. After drying in a nitrogen current, the catalyst is placed in acatalyst chamber which is adapted to be heated and, if necessary,capable of being cooled. Thereupon, pre-purified acetylene, as requiredby standard practice in a quantity of 30 to 40 liters per hour is passedthrough the chamber at a temperature of 155-165 C. The temperature isadvantageously held as constant as possible, which may be attained byartificial cooling or corresponding regulation of the acetylene supply.The reaction products which are. formed in a practically quantitativeyield from the converted acetylene are removed from the waste gas bycooling, compression or dissolution, said reaction products Example 2 Amixture of 300 g. of cuprous chloride, 100 g. of mannite and 50 g. ofmagnesium chloride is formed into a dough with water and deposited uponpumice stone after which it isdried in a nitrogen current. Acetylenewhich contains small quantities of acetic acid is conducted over thecatalyst thus obtained at a reaction temperature of Fla-180 C. Theoutput is just as favorable as in the example cited above. y

The invention claimed is:

1. Process for producing monovinyl acetylene which comprises passingacetylene through a solid catalyst containing a cuprous salt, magnesiumchloride and an aliphatic polyhydric alcohol. a

2. Process *for producing monovinyl acetylene which comprises passingacetylene at a temperature of 100-180 C. through a solid catalystcontaining a cuprous salt, magnesium chloride and which comprisespassing acetylene at a temperature of 100-180 C. through a solidcatalyst containing a cuprous salt, magnesium chloride and an aliphaticpolyhydric alcohol, said catalyst being applied on a carrier.

carrier and having its emcien'cy increased by admixingwith the acetylenevapors a volatile carboxylic acid. V

8. Process for producing monovinyl acetylene which comprises passingacetylene at a temperature of 100-180 C., and ina quantity greater thanis to be converted in the reaction, through a 7 solid catalystcontaining. a cuprous salt, magcreased by-admixing with the acetylenevapors a volatile carboxylic acid.

10. Process for producing monovinyl acetylene which comprisespassingacetylene at a temperature of 100-180 C.,-and in a quantity greater thanis to be converted in the reaction, through a solid catalyst containinga cuprous salt, magnesium chloride and an aliphatic polyhydric alcohol,the eificiency of said catalyst being incohol, removing the reactionproduct from the acetylene and returning the latter to the reaction zonewhile replenishing the converted acetylene with fresh gas.

11. Process for producing monovinylacetylene which comprises passingacetylene at a tempera ture of 100-180 C., and-in a quantity greaterthan is to be converted in the reaction, through a solid catalystcontaining a cuprous salt, magnesium chloride and an aliphaticpolyhydric alcohol, said catalyst being applied on a carrier and havingits efliciency increased by admixing with the acetylene vapors avolatile carboxylic acid, removing the reaction product from the 5.Process for producing monovinyl acetylene which comprises passingacetylene at a temperature of 100-180 0. through a solid catalystcontaining a cuprous chloride, magnesium chloride and glycerin, saidcatalyst being applied on a carrier. V

6. Process for producing monovinyl acetylene which comprises passingacetylene at a temperature of 100-180 C. through a solid catalystconacetylene'and returning the latter to the reaction zone whilereplacing the converted acetylene with fresh gas.

12. Process for producing monovinyl acetylene which comprises passingacetylene at a temperature of 100-180 C., and-in a quantity greater thanis to be converted in the reaction, through a solid catalyst containinga cuprous chloride,

- taining a cuprous salt, magnesium chloride and 4 an aliphaticpolyhydric alcohol, the emciency of said catalyst being increased byadmixing with the acetylene vapors a volatile carboxylic acid.

magnesium chloride and glycerin, said catalyst being applied on acarrier and having its efllciency increased by admixing with theacetylene vapors a volatile. carboxylic acid, removing the reactionproduct from the acetylene and returning the latter to the reaction zonewhile replacing CERTIFICATE OF CORRECTION. Patent No. 2,153,051; May 16,19 9. HERBERT BERG; ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page '2,first column, line 16; for "179-180 0." read 17o-1go .;and that the saidL'etters Patent shouldbe read with this correction therein that the samemay conform to the record of the case in the Patent Office. I I

Signed and. sealed this 15th day of June, A. D. 1959 Henry Van Arsdale,(Seal) Acting Commissioner of Patents.

